Compared with a CRT (cathode ray tube) display, the LCD has the advantages of less weight, smaller volume, and lower radiation. Hence, we can expect that the LCD will substitute the CRT display as popular display in the future.
Conventional LCDs include a liquid crystal panel and a back light device. The liquid crystal panel includes a top substrate, a bottom substrate and a liquid crystal layer formed between the top substrate and the bottom substrate. The top substrate has a CF (Color Filter). The bottom substrate has a TFT (thin film transistor). Beside, a top polarizer is disposed on the top substrate and a bottom polarizer is disposed between the bottom polarizer and the back light device.
A Black Matrix may be plated on a CF to increase contrast and prevent mixture of colors and leakage of light. Hence, the LCD is better than the CRT display in resolution. However, if the resolution is enhanced without narrowing the pitch of the pixels, the aperture ratio of pixels will be reduced and the brightness of the LCD will decrease. Hence, narrowing of the Black Matrix or other alternatives to improve the brightness is an important issue.